Studies in Drying: Through-Circulation and Rotary Systems

[摘要] For the accurate design of a system in which a transfer process such as drying is taking place, the effects of the dominant variables in the system must either be determined experimentally or predicted from reliable empirical or theoretical correlations. Reliable predictions may be made when the transfer process is occurring under steady state conditions, as in the constant rate period of drying. When the transfer rate varies and depends on the system being investigated as in the falling rate period of drying, the effect of the controlling factors should be determined experimentally. In the present work, drying tests have been conducted using two systems which are distinguished by the type of design procedure necessary for each system. The two series of drying tests were designed: (1) to permit the prediction of heat and mass transfer rates during the constant rate period of drying of spheroidal Celite pellets arranged in a packed bed (2) to apply the "factorial" method of experimentation to the drying of barley in a rotary dryer. 1. Packed Bed Tests. Tests have been carried out to determine the effect of air flow, air temperature, depth of pellet bed and size of pellet on the constant drying rate of Celite pellets arranged in a packed bed. The ranges of the factors studied were: air flow 300 - 875 lb/h ft2 dryer area air temperature 35 - 60

[发布机构] University:University of Glasgow

[关键词] Chemical engineering